A Thank You to the members about low voltage

pianotuna wrote:
Hi,

I use a hair dryer to check voltage under load.

Would you care to elaborate about how campgrounds used to be wired vs how it is now?

myredracer wrote:
Checking a pedestal's voltage before plugging in or even backing into a site is not a bad idea but realize that you're testing open circuit voltage and it could drop out of sight with a load on it. Low voltage is common, esp. during the summer heat and in older CGs (due to how they used to wire them).

Nowadays they use those gray metal, direct burial enclosures like in the 1st photo. They have 125 or 200 amp feed-through lugs and by NEC demand rules, can have up to 6 or 7 pedestals (going by memory here on a run of 200 amp wire/cable back to the distribution transformer. Because of "diversity" (not all loads operating a full or high demand loads at the same time), the voltage drop at any one pedestal can be significantly reduced. If you happened to be the only site on a run of loop-fed pedestals, you could have a 30 or 50 amp RV fed by 200 amp wire. These loop-fed pedestals are more efficient electrically and cost less overall to install.

In the olden days, they still had distribution transformers (those pad-mounted boxes you'll see around a CG) but they had panels (100 or 200 amps) mounted on posts distributed around a CG and individual 30 amp or 50 amp runs to pedestals. "Pedestals" were a 30 or 50 amp recept. (and a 20 amp GFCI) and breakers in an enclosure similar to the 2nd photo mounted on a wood post. Sometimes there can be 2 or 3 of these pedestals combined on a run of heavier gauge wire which can serve 2 side-side sites or be some distance away from each other. I've seen some of these older pedestals with a single 30 amp run of #10 quite a distance from the panels. These older pedestals are wired in a "star" configuration in comparison with today's loop-fed design. There's also a lot of variation in exactly how they were wired.

An issue with older CGs is all the 50 amp RVs that are being sold these days. The 50 amp RVs use an adapter but can easily draw loads up to 30 amps, whereas most 30 amp RV owners are used to conserving power and maybe draw 15-20 amps at most on average. The 2017 edition of the NEC has substantially increased the demand load requirement for 50 amp RVs too.

Prior to 2005, the NEC only required 5% of CGs to have 50 amp pedestals (unless they voluntarily built above code min.). So in older CGs you can have a LOT of 50 amp RVs running off 50-30 amp adapters and drawing significantly more power than the original code demand allowance which will also exacerbate voltage problems.

If you pull into an older CG and have a choice of sites, it can sometimes help to pick one closest to a transformer or panel instead of ending up at the farthest end of a run.

Worst CG wiring I've seen was at a CG in Oregon where they had individual #10 romex runs strung overhead between the trees and then an outlet dangling below. Def. not good voltage and def. not to code.

Hope this explains it well enough. A drawing might be better if I had one. If you've ever seen a guy opening panels in a CG and taking photos and notes, that was probably me... :)